The present invention generally relates to electronics. In particular, the invention relates to systems and methods for cooling substrate-supported heat-generating components of electronic devices.
There is a continuing demand for electronic devices to be made smaller and to operate faster and at higher levels of power. However, the reliability of small, fast-operating, high-power electronic devices oftentimes is limited by the heat produced by such devices. More specifically, the performance of an electronic device can be hindered if excess heat is not removed.
By way of example, excess heat can cause components of an electronic device to develop cracks. Typically, these cracks are caused by differences in the thermal coefficients of expansion of materials used in the components. Of particular interest, cracks can produce electrical discontinuities, such as by separating leads, and/or can result in mechanical failure of a substrate upon which another component is mounted. Additionally, excess heat can affect electrical properties, e.g., resistance, of electrical components.
In order to remove excess heat from an electronic device, some packaging techniques rely on conductive transport of heat to an internal heat sink of the device. As is known, such a technique oftentimes is inadequate for dissipating large, localized heat fluxes that can be associated with electronic components.
Based on the foregoing, there is a need for improved systems and methods that address these and/or other perceived shortcomings of the prior art.
The present invention involves cooling of heat-generating components that are supported by substrates. In particular, the invention involves compressing a cooling fluid within a substrate and then expanding the cooling fluid to remove heat from components that are thermally coupled to the cooling fluid. By removing heat from a substrate and/or heat-generating components supported by the substrate, the tendency of an electronic device to exhibit heat-related failures is reduced.
A system in accordance with the invention includes a substrate and a heat-generating component supported by the substrate. The substrate supports a microcompressor that compresses a cooling fluid. A heat exchanger is supported by the substrate, receives cooling fluid from the microcompressor, and removes heat from the cooling fluid. A microexpander is arranged at least partially in the substrate and receives cooling fluid from the heat exchanger. The microexpander expands the cooling fluid and thermally couples the cooling fluid to the heat-generating component so that heat is removed from the heat-generating component.
Micromachined components can be used to facilitate cooling. For instance, micromachined compression stages of a microcompressor and/or micromachined expansion stages of a microexpander can be supported by, e.g., formed at least partially in, a substrate.
Based upon the requirements of the particular application, a microexpander can be sized and/or shaped for routing cooling fluid in various manners. For instance, the microexpander can be a serpentine-shaped structure that routes cooling fluid to multiple locations about a substrate.
Various cooling fluids can be used. For instance, a gas, such as air or nitrogen, or a liquid, such as water or liquid nitrogen, can be used depending upon the particular application. Note, a phase-change medium that changes state from a liquid to a gas and vice versa can be used.
A method in accordance with the invention for cooling a heat-generating component that is supported by a substrate includes compressing a cooling fluid within the substrate. The cooling fluid then is expanded to remove heat from the heat-generating component.
Clearly, some embodiments of the invention may not exhibit one or more of the advantages and/or properties set forth above. Additionally, other systems, methods, features and/or advantages of the present invention will be or may become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features and/or advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.